Otto kroll



UNITED STATES PATENT OFFICE,

OTTO KROLL, OF BERLIN, GERMANY.

PROCESS OF MAKING INCANDESCENT BODIES FOR GAS-BURNERS.

SPECIFICATION forming part of Letters Patent No. 564,430, dated July 21, 1896.

Application filed November 4, 1895, Serial No. 567,917.

(No specimens.)

Patented in England February '7, 1895, No. 2,782; in

France February 7, 18951 No. 244,954; in Belgium October 10, 1895, 110,117,834, and in Italy October 17,1895, No.

To aZZ whom it may concern.-

Be it known that I, OTTO KROLL, a subject of the German Emperor, residing at Berlin, German Empire, have invented a new and useful Process of Making Incandescent Bodies for Gas-Burners, (for which I have obtained patents in Great Britain, No. 2,7 32, dated February 7, 1895; in France, No. 244,954, dated February 7, 1895; in Belgium, No. 117,834, dated October 10, 1895, and in Italy, No. 39,964/247,

dated October 17, 1895,) of which the following is a description.

The incandescent bodies hitherto in use for incandescent gas burners, which are made by impregnation with a solution of rare refractory earths or salts or other suitable substances, present the disadvantage that the illuminating power greatly decreases after a short time, which in most cases is caused by the shriveling of the incandescent body. The incandescent bodies so far known do not possess a rigid refractory frame sufficiently proof against the action of the heat.

My invention has for its object to provide an incandescent body possessing a hitherto unattained strength and rigidity.

My invention also makes it feasible to combine the oxids of zirconium and magnesium, having comparatively little illuminating power, with an incandescent body in exceed ingly thin layers, so that these two materials obtain such light-emitting capacity as is otherwise only secured by using mixtures of the well-known rare and high-priced refractory earths. This result is attained by means of the peculiar construction of the new incandescent body, whichhas a very fine porous frame, the single filaments of which, in consequence of their rough, fiossy surface, are capable of emitting more light than yielded by the well-known smooth-surfaced bodies. The materials used for the formation of incandescent hoods or mantles, such as zirconium, salts of alkaline earths, alkaline metals, &c., are not used in my improved process for this same purpose of constituting the frame proper of the incandescent body. On the contrary, these rare materials are only used for the purpose of impregnating or coating a rigid refractory frame formed in the manner hereinafter described.

The frame proper of my improved incandescent body is obtained as follows: I take twenty per cent. (20%) potassium chlorid (K01); forty per cent. (40%) nitrate of barium (BaNO 2), and forty per cent.

(40%) carbonate of barium (BaOO and dissolve these compounds separately or all together, preferably in nitric or muriatic acid. When using nitric acid, I obtain a liquid consisting of nitrate of potassium (KNO and nitrate of barium (BaN O If I use muriatic acid the solution will consist of a mixture of potassium chlorid (K01) and barium chlorid, (BaOR) This solution is evaporated, whereby a residue is obtained containing the above-named bodies so finely and thoroughly mixed as could not be obtained by mechanical means. is then heated up and kept in a condition of White heat for a considerable time, until the substances become still more thoroughly mixed by melting. This heating is effected in retorts, crucibles, or other suitable refractory devices and preferably without the admission of air, so as to prevent any loss through evaporation or a disagreeable smell caused by the escaping chlorin. The product is then mixed with an abundant quantity of diluted sulfuric acid and boiled so as to make the mixture liquid. Part of the residue is thereby dissolved, and I obtain sulfate of potassium, (K SO in solution, and an insoluble compound of sulfate of barium, (BaSO but these insoluble substances are in an exceedingly fine state of division in the excess of diluted sulfuric acid and mixed with a solution of sulfate of potassium, so that a thin milky liquid is obtained,.which I use for the impregnation of fabrics, filaments, threads,

and other combustible materials. The liquid is partially absorbed by the fabric, while the finely-divided insoluble particles sus- The residue pended in the liquid penetrate by capillary attraction into the pores of the fabric or settle on the surface of the same. The piece of nesium, strontium, zine, aluminium, zirconium,lanthanum,cerium,yttrium,didy1nium, thorinum, or other suitable materials, where upon it is dried and heated a second time. I thus obtain an incandescent body or mantle of an illuminating capacity equal to that of all mantles hitherto known, and at the same time more durable, inasmuch as the new refractory frame does not shrink. Notwithstanding its greater durability and eX- lent incandescent properties, my new mantle can be made at a lower cost than those now in use, because my mantle consist-s of a cheap refractory frame coated or impregnated with the expensive incandescent materials, while the mantles hitherto known consist entirely of this expensive material.

It is obvious that instead of coating the frame with the incandescent materials they may be added to the above-described solution used for the impregnation of the fabric.

The incandescent body produced by my new process will retain its form and its incandescent properties after having been used for a thousand hours or more.

Having now described my invention, what I claim, and desire to secure by Letters Patcut, is

1. The process of making a base or frame for incandescent mantles, consisting in impregnating a combustible substance with a mixture of potassium chlorid, nitrate of barium and carbonate of barium, substantially as and for the purposes described.

2. In the making of incandescent mantles,

the process of forming an impregnating mixture for a frame or base for the incandescent material, consisting in first, dissolving potassiumchlorid, nitrate of barium and carbonate of barium in nitric or muriatic acid; sec ond, evaporating the solution; third, heating the residue to a white heat under the exclusion of air; and fourth, mixing the product with diluted sulfuric acid, substantially as and for the purposes described.

3. The process of making incandescent bodies, consisting in impregnating a body or substance with a mixture of potassium chlorid, nitrate of barium, and carbonate of barium, to form a base or frame, and rendering said base or frame incandescent by coating or impregnating it with solutions of suitable refractory substances, for illustration: oxids of calcium, magnesium, strontium, zinc, aluminium, zirconium, lanthanum, cerium, yttrium, didymium, or thorinum, substantially as and for the purposes described.

a. An incandescent mantle formed of a base or frame of potassium chlorid, nitrate of barium and carbonate of barium, treated in the manner set forth and coated or impregnated with suitable refractory incandescent substances, substantially as described. In witness whereof I have hereunto set my hand in presence of two witnesses.

OTTO KROLL. lVitnesses:

IV. HAUPI, E. ZIEMS. 

